Vibroflotation VF

7/27/2019 Vibroflotation VF

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Vibrofotation (VF)

ground improvement specialists


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First attempts o using the Vibrootation (VF) technology, also known as a vibrocompaction method,

took place in the year 1934. Since then, the method o the loose soil compaction has been repeatedly

improved and is in use till the present day. Currently, the method is applied in projects around the world

and is one o the leading methods o improvement o non-cohesive soils.

Technology specication

The Vibrootation (vibrocompaction) is a method o improvement o non-cohesive soils by re-arranging

the grain distribution pattern while applying cyclic vibrations which cause the outow o granular soil.

As a result, the compaction o soil and the pore volume reduction are obtained. The main equipment usedor the vibrocompaction is heavy plunge vibrators called vibroots.

The vibroots are cylindrical in shape with a diameter ranging rom 30 up to 50 cm; the drive unit is

mounted in the bottom part generating lateral vibrations with an amplitude ranging rom 5 up to 20 mm.

Oen, the bottom part o the vibroot is equipped with jets where water or air is pumped in order to enhance

the soil compaction. The vibroot with a leading pipe penetrates the ground under its own weight or in

case o the vibroot suspended on the sel-support structure under the pressing orce with simultaneous

action o vibration. The compaction occurs as the vibroot is surged up and down. In the loose soil the

compacted column has a diameter ranging rom 1.5 up to 2.5 m depending on the grid o compaction

points and the type o soil.

When compacting loose soil the ground surace is lowered. The depression in the ground surace dependson the thickness o the compacting layer and the degree o loosening the soil to be compacted.

In any case, it is necessary to compact the surace layer between 0.5 and 1 m which is loosened by the

application o the vibrootation. For this purpose the conventional equipment such as heavy vibrating road

rollers is used.


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Application

The Vibrootation (VF) is best suited or non-cohesive soils such as loose sands, gravels and sandy

gravels. Good results are obtained or non-cohesive mining waste, etc. which contains up to 5% o nes:

silts and clays. The soils containing over 10% o silt and clay raction are not suitable or this method.

The Vibrootation (VF) is oen used or the compaction o thick silted up surace lls on ooded

areas - the silting method.

The Vibrootation (VF) can be used or the oundation o various acilities such as parking lots, airport

runways, road embankments, enclosed buildings and structures on areas reclaimed rom the sea

(harbors, hydraulic structures). This method is particularly well suited or the oundation o acilities

with uniormly distributed pressure onto the subsoil.

The use o the VF method in non-cohesive soils signicantly reduces the soil settlement aer applying

loads, decreases the soil ltration coecient and leads to the unication o the oundation conditions

(minimization o the diferential settlement).

Compaction points the vibroot is introduced into the soil in a triangular or square grid with the side

dimensions ranging rom 1.5 up to 5,0 m. The depth o the compaction varies rom 3.0 m up to

20.0 m, but it can be carried out up to 40 m. The obtained compaction index (Id) is ranging rom

0.5 up to 0.9.

The vibrootation is oen applied as an auxiliary operation in cases where it is impossible to avoid deep

oundation. In such cases the vibrocompaction o the subsoil helps to achieve sucient compaction

index which avors piling and allows or shallow oundation o the acility oors.


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Menard Polska Sp. z o.o.

ul. Kochanowskiego 49 A01-864 Warszawa

[email protected].: +48 22 560 03 00, fax: +48 22 560 03 01

Advantages:

Economy one o the most economicalmethods o the soil improvement,

particularly efective in case o deeply

deposited non-cohesive soils.

Comprehensive improvement applied to improve geotechnical

parameters o compacted soils in the

entire volume.

Simplicity o implementation application o this technology does not

require delivery o materials, additional

equipment. The success o the project

depends on the proper selection ooperational parameters o machines and

location o compaction points.

Settlement control application o theVF technology leads to the reduction o

settlements and minimizes diferential

settlements which signicantly contributes

to sae oundation o the structures.

Scale o operation one o the ewsoil compaction technologies used or the

layers with considerable thickness up to

a depth o 40 m.

Hydraulically eective thistechnology is oen used or hydraulic

structures such as harbor bottoms,

improvement o quays; it is the only

efective method o improvement o the

soil conditions.

High perormance the VF technology

is highly efective reaching several

thousand o cubic meters o improved

soil per day (using a single working unit).

Documents

Vibroflotation VF